Tricharaea grade

Tricharaea grade

This grade is composed of Bahamiola , Sarcofahrtiopsis (including Pacatuba ) and Tricharaea , which correspond to the three first splits of the ‘lower’ Sarcophaginae ( Fig. 2A View Figure 2 ). The monophyletic genus Tricharaea is positioned near the base of the subfamily, as sister to the remaining Sarcophaginae . The phylogenetic closeness between genera of the Tricharaea grade was inferred in a cladistic study by Lopes (1990), who included them in the tribe Sarothromyiini together with Nephochaetopteryx and Rettenmeyerina . Reduction in the number of setae on the meron was suggested as a synapomorphy for members of the tribe Sarothromyiini ( Lopes, 1990) , whose phylogenetic arrangement showed a monophyletic Tricharaea [in the wide sense of Pape (1996)] as sister taxon of the clade ((( Pacatuba + Sarcofahrtiopsis ) + Bahamiola ) + (Nephochetopteryx + Rettenmeyerina )). This is the only published topology for all genera of the Tricharaea grade before the current study, and it is partially supported by our results in that we also found Tricharaea to be monophyletic, as well as a clade consisting of Sarcofahrtiopsis species (including Pacatuba ). However, in the broader context of the present analysis, many of the similarities shared by these genera appear to be symplesiomorphic. A basal position of the genus Tricharaea was first inferred by Roback (1954) and Lopes (1983) in their non-cladistic studies. The first author implied this position based on male terminalia characters, while the second one used characters from the cephaloskeleton of the first-instar larvae. This assumption was later corroborated by Pape (1994) and Giroux et al. (2010), who also found Tricharaea to be the sister taxon of the remaining sarcophagine flies included in their morphology-based phylogenetic analyses. In Kutty et al. ’s (2010) tree, Sarcofahrtiopsis cuneata (Townsend, 1935) was found as sister species of Tricharaea occidua (Fabricius, 1794) , and these emerged together in the lower part of the Sarcophaginae , although not at the base and with no branch support. In their molecular studies, Kutty et al. (2010) recovered a polyphyletic genus Tricharaea , and Stamper et al. (2012) had their single included species of Tricharaea as the sister taxon of ( Tripanurga + Boettcheria ), and not as part of the ‘lower’ sarcophagines. Recently, the molecular study by Piwczyński et al. (2014) showed a clade consisting of S. cuneata and a monophyletic Tricharaea placed at the base of the Sarcophaginae , but with no branch support. A sister-group relationship between Sarcofahrtiopsis and Tricharaea is not supported here and its recovery in other studies can be interpreted as being due to incomplete sampling or to a different homology assessment. We found support for a basal position of Tricharaea and the lineages of Bahamiola and Sarcofahrtiopsis (including Pacatuba ) (clades 4–9 in Fig. 2A View Figure 2 ) splitting off next from the remaining Sarcophaginae . With part of the molecular evidence from previous studies, and with the morphological data from both adults and larvae found here and in previous studies being in favour of a basal position of Tricharaea , we consider this as the better-supported placement for this genus.

It is noteworthy that the four genera of theTricharaea grade share a fair number of features not found outside this group, yet they emerge as paraphyletic in our analysis. The following shared character states would appear particularly relevant in this context: proclinate fronto-orbital setae in males (‘pc’ in Fig. 41 View Figure 41 ), notopleuron without subprimary setae (‘nt’ in Fig. 41B–D View Figure 41 ), two katepisternal setae, postalar wall bare, wing vein R 4 + 5 with dorsal setulosity reaching crossvein r-m, ST5 with posterior margin straight or with a shallow concavity ( Fig. 42A, B View Figure 42 ), ST5 with a central patch of setae ( Fig. 42A View Figure 42 ), vesica divided into a proximal and a distal section ( Fig. 25A–D View Figure 25 ), vesical arm-shaped lever elongated to very elongated ventrally ( Fig. 25A–D View Figure 25 ), vesical arm-shaped lever with a hammer-shaped or bilobed to oval apex ( Figs 19H View Figure 19 , 27A View Figure 27 , 28H, J View Figure 28 ) and distal section of the vesica globose, with small denticles ( Figs 19E View Figure 19 , 28G, H View Figure 28 , 39H View Figure 39 ). The last five character states are found only in species of the Tricharaea grade . The genera Bahamiola and Sarcofahrtiopsis (including Pacatuba ) do not form a monophyletic group, but they share a vesical arm-shaped lever very elongated ventrally ( Figs 15H View Figure 15 , 19E View Figure 19 , 28H View Figure 28 ) and a hood-shaped juxta with a denticulated lateral margin that is enlarged ventrally to form a capsule-like structure ( Figs 15G View Figure 15 , 19E–G View Figure 19 , 28H, J View Figure 28 , 30A, B View Figure 30 ). Additional characters and a larger sample of outgroup taxa will be a proper test of this topology, and therefore of the polarity of the character transformation series involved in the evolution of the ‘lower’ sarcophagines.

The monophyly of Tricharaea was previously supported by molecular data ( Piwczyński et al., 2014), but here it is also supported by four autapomorphies: epandrium brownish (not reddish), vesical arm-shaped lever elongated ( Figs 25A View Figure 25 , 27A View Figure 27 ), juxta smooth laterally and wrinkled medially ( Figs 27A View Figure 27 , 39H View Figure 39 ), juxta funnelshaped ( Fig. 39H View Figure 39 ). Within the Sarcophaginae , two plesiomorphic character states are shared by the three taxa of Tricharaea and Paramacronychiinae : postgena angled in lateral view ( Fig. 41D, E View Figure 41 ), and sparse, weak anepimeral setulae (‘as’ in Fig. 41D View Figure 41 ). In the handmade cladogram of the tribe Sarothromyiini, Lopes (1990) argued for the monophyly of Tricharaea based on its species sharing spherical spermathecae. Later, Pape (1996) used this character state plus five features of male terminalia structures, three of female terminalia and one of the puparium, to diagnose the genus Tricharaea . Pape’s (1996) male character states were: (1) male with at least one strong proclinate orbital seta, (2) postalar wall bare, (3) metasternum setulose, (4) male ST5 with a central patch of setae, (5) terminalia brownish (not red), (6) spermathecae spherical, (7) female with an epiproct and (8) puparial spiracles not in a recession. Except for female and larval character states 6–8, all others were included here, and only character states 1 and 5 (slightly modified) were found to be autapomorphic for this genus. However, all of Pape’s (1996) character states and the two plesiomorphic and one autapomorphy found in the present study are used to diagnose this genus.

With a single species, the genus Sarcofahrtiopsis was described by Hall (1933) based on ST5 not having a cleft. Dodge (1965b) added more character states to the diagnosis of this genus, such as the hind coxa bare posteriorly, wing vein R 1 setulose and proclinate orbital setae present in males. Later, Lopes (1990) suggested the setulose wing vein R 1 and the long and bristly pregonite as synapomorphies; however, the first character state is also shared with genera such as Helicobia , Malacophagomyia (including Dodgeisca ), Nephochaetopteryx , Panava , Promayoa , Rafaelia , among others, and the second character state does not diagnose Sarcofahrtiopsis , as it is not present in all species of the genus. Pape’s (1996) diagnosis included the mentioned character states plus the following: notopleuron with subprimary setae, postalar wall bare, metasternum bare, third costal sector of wing bare ventrally, male ST5 with a central patch of setae, terminalia usually black, spermathecae elliptical and female without an epiproct. Finally, Mello-Patiu & Pape (2000) discussed all these features and suggested a list of 16 character states as a generic diagnosis of Sarcofahrtiopsis , highlighting the reduced metasternal setosity and the slender and elongated parameral (=postgonal) apodeme as autapomorphies. From these, the slender parameral apodeme should probably be removed as an autapomorphy, since this structure is not elongated in Sarcofahrtiopsis thyropteronthos Pape, Dechmann & Vonhof, 2002 ( Pape, Dechmann & Vonhof, 2002). Here, the 13 male character states of Mello-Patiu & Pape (2000) were analysed and only the reduction in the setosity of the metasternal area came out as autapomorphic for Sarcofahrtiopsis .

Neither the monospecific genus Pacatuba nor the polyspecific genus Bahamiola of the classification of Pape (1996), here represented by a single species only, were found to possess any autapomorphies. However, Pacatuba and Sarcofahrtiopsis share one autapomorphy, vesical arm-shaped lever very elongated (twice its full length). The clade of Sarcofahrtiopsis (including Pacatuba ) received aBS and weak JK support; however, Pacatuba shares 10 out of the 13 male character states listed by Mello-Patiu & Pape (2000) to define Sarcofahrtiopsis . Therefore, we suggest Pacatuba as a new synonym of Sarcofahrtiopsis . Consequently, we present a new generic diagnosis for Sarcofahrtiopsis , which is divided into the two subgenera Pacatuba , new status, and Sarcofahrtiopsis (s.s.), for which we also include subgeneric diagnoses.